Die casting machine with trimmer



3,495,650 DIE CASTING MACHINE WITH TRIMMER 1 G. PERRELLA 5 Sheets-Sheet 1 Feb. 17,, 1970 Filed May 5, 1967 G. PERRELLA DIE CASTING MACHINE WITH TRIMMER Feb. 17, 1970 5 Sheets-Sheet 2 Filed May 5, 1967 Feb. 11', 1970 Filed May 5, 1967 G. PERRELLA DIE CASTING MACHINE WITH TRIMMER 5 Sheets-Sheet 3 Feb. 17, 1970 G. PERRELLA DIE CASTING MACHINE WITH TRIMMER Filed May 5, 1967 5 Sheets-Sheet 4 Feb. 17, 1970 s. PERRELLA 3,495,650

DIE CASTING MACHINE WITH TRIMMER Filed May 5, 1967 5 Sheets-Sheet 5 United States Patent 3,495,650 DIE CASTING MACHINE WITH TRIMMER Guido Perrella, Montreal, Quebec, Canada, assignor to Dynacast Limited, Montreal, Quebec, Canada Filed May 3, 1967, Ser. No. 635,860 Claims priority, application Canada, Feb. 14, 1967, 982,860 Int. Cl. B22d 17/00 US. Cl. 164-262 3 Claims ABSTRACT OF THE DISCLOSURE A die casting machine having a valve structure integrated with the zinc furnace or pot and being mechanically operated by a rocker arm and cam lobe system. The machine includes a trimming device that consists of a second pair of dies that operate on the casting after it is removed from the forming dies so as to remove any flashing from the casting. This obviates the necessity of tumble trimming and similar operations.

This invention relates to die casting machines and in particular to a die casting machine that is both mechanically operated and which includes means for trimming flashing and sprue from a cast piece, such trimming being effected during the operation of the machine.

The trimming of die castings, especially precision castings, is normally a subsequent and costly operation of the die casting process. With miniature or sub-miniature castings especially, trimming is a costly step inasmuch as such castings are made in relatively high numbers and the trimming normally has been carried out with a barrel tumbling type of operation to remove gates and like flashing. The material removed is then remelted for recasting.

The object of the present invention is to provide a die casting machine incorporating an operative trimming element in its structure and which is actuated from the same drive means that actuates the other elements of the die casting machine. In effect, the machine includes two sets of dies, one for casting and one for trimming. In accordance with the invention then, a die casting machine comprises a frame, means for supporting and guiding dies and cores on the frame and a pot pivotally secured to the frame. There is also provided means for injecting a casting metal such as zinc into the dies, with the injection means being integrally formed with the pot. Finally, there is also provided trimming means for displacing a casting from the dies and then removing flashing and the like from that casting. The apparatus includes drive mechanism for actuating the dies and cores, pivoting the pot and its injection means into operative engagement with the dies, and operating the trimming means.

The invention will now be described by way of example with reference to the accompanying drawings wherein:

FIGURE 1 is a perspective view of the die casting machine of the present invention;

FIGURE 2 is a plan view of the machine shown in FIGURE 1;

FIGURE 3 is a side elevation view of the machine of FIGURES 1 and 2;

FIGURE 4 is a sectional view taken along the line 44 of FIGURE 2;

FIGURE 5 is a fragmentary, sectional view of the trimming mechanism shown in full elevation in FIGURE 3; and

FIGURE 6 is a sectional view of the trimming mechanism taken along the line 66 of FIGURE 5.

Referring to FIGURE 1, the die casting machine comprises drive means generally illustrated at 2; a die and "ice core arrangement at 4; a combined pot and injection system shown at 5; and a trimming device generally indicated at 6. Shown in FIGURE 2, the machine includes a frame 1 supporting a pair of dies 10 and cores 12. Dies 10 and cores 12 are secured to their respective shanks 14 and 16, respectively. The dies 10 are brought into face-to-face engagement with one another by means of rocker arms 18 pivotally connected to the frame: 1 as at 20 and operated by the drive means 2 through cam followers 22. Similarly, the cores 12 are operated vie cam followers 24, one of the cores being remote from the drive means 2 and being actuated through the intermediary of a bell crank 26 and connecting rods 28 and 30. The drive means, in this case a rotated cam shaft, actuates the dies and cores by means of cam lobes to bring the members into engagement with one another and the followers such as 22 and 24 are maintained in contact with their respective lobes by means of springs, not shown.

DRIVE MEANS Referring to FIGURES 3 and 4, the drive means comprises a cam shaft 32 having a plurality of lobes thereon, with the lobes driving all elements of the die casting machine. The cam shaft 32 is rotated, for example, from electric motor 34 (FIGURE 2) through a reduction gear box 36, chain 38 and sprocket 40 illustrated in section in FIGURE 4. The cam shaft 32 as shown in FIGURE 4 comprises two main sections, an inner stationary member 32a which is secured by cap screws 44 to the frame member 1 and an outer portion 32b. The outer portion is rotatable with respect to the inner portion and the mount ing between the two portions is effected by roller bearings 46.

As shown in FIGURES 3 and 4, the shaft 32 carries two upper lobes 48 and 50 which operate the cores 12 of the machine. The next lowermost lobes 52 and 54 are adapted to operate the dies 10 through the rollers 22 and rocker arms 18. Following on down on the cam shaft, the chain sprocket 40 is then secured to a flange portion of the shaft and this is adjacent to a further lobe 56 for operating one portion of the trimmer mechanism to be described further on in the specification. All of the above-mentioned lobes are situated transverse to the rotational axis of the cam shaft and these are followed by a first cam slot 60 which operates a further portion of the trimmer mechanism and lastly, a surface lobe 62 for actuating the means to pivot the pot and injector mechanism 5.

POT AND INJECTION SYSTEM As shown in FIGURE 2, the pot .5 is suspended by and pivoted from two arms 64 and 65. Turning to FIG- URE 4, the pot includes an injection system comprising a sleeve 68 having a piston 70 slidable therein by means of a connecting rod 72 that is actuated in a vertical manner by an air cylinder or the like 74. The lower end of the piston 70 terminates at a compression chamber 76 which is interconnected to a nozlle 78 by means of a conduit 80. The inflow of molten zinc from the pot into the chamber 76 is governed by a single ball Valve 82 as shown or by a valve system of the type shown in copending application Ser. No. 682,146 filed Nov. 13, 1967. The nozzle 78 is brought into and out of engagement with a channel (not shown) in the dies 10 by means of a rocker shaft connected operatively to the cam shaft 32.

The frame 1 of the machine is provided adjacent the nozzle portion of the pot with a sleeve type bushing 84 which contains a bolt and socket 86 and 88, respectively, the bolt being maintained away from the socket by means of a spring 90. The upper end of the socket bears against a buffer 92 adjacent the nozzle 78. The head of the bolt 86 bears against one end of a rocker 94 that is pivoted about a point 96, the operative end of the rocker 94 being held in engagement with the lobe surface 62 of the cam shaft. See FIGURE 6. The surface 62 of the cam is engaged by a roller 98 on the end of the rocker 94. It will be appreciated that as the operative end or the roller 98 of the rocker shaft 94 is moved downwardly by the cam surface 62, the opposite end will be moved upwardly against the bolt head 86 to therefore push upwardly on the buffer 92 and bring the nozzle 78 into engagement with dies for an injection of zinc therein.

TRIMMING DEVICE Turning to FIGURE 5, the trimming device 6 shown generally in FIGURE 1 includes a T-shaped cross head 100 secured to a vertically slidable post 102 mounted in the frame of the machine. The lower end of post 102 is connected to an actuating arm 184 by means of a yoke 106. The other end of arm 104 is pivotally secured at 108 to the machine frame adjacent the base of the cam shaft 32 and intermediate the length of the arm 184 there is provided a roll-type follower 110 which runs into the cam groove 60 shown in FIGURE 4. It will be obvious from FIGURE that as the cam 32 rotates and the follower 110 travels within the groove 60 the post 102 will be raised up and down in a vertical orientation by the arm 104.

It will be appreciated from FIGURES 5 and 2 that the cross head 100 includes a pair of diametrically opposed arms 112 and 114 each supporting a gripping member 116 which is adapted to be connected to the casting between the two dies through the means of a gate in the die face. While arm 112 and its gripping member 116 is in such a position, for example that shown in FIGURE 2, its opposing arm 114 having an identical gripper 116 is disposed between a pair of identical dies 118 which are adapted to remove any flashing and sprue from the casting by being actuated through a pneumatic device 120. After an injection is made, the post 102 is raised up, the arms 11.2 and 114 are moved 180 so that the casting is dropped downwardly into position and the dies 118 are then brought over the casting and the actuation of the device 120 trims the casting.

In addition to the arm 104 for raising and lowering of the post 102, there is also provided a first arm 122 for turning the cross head 180 and a second arm 124 which pivots the dies 118 and vacuum 120 from inoperative to operative positions as shown in FIGURE 2. The arms 122 and 124 have a common connection to a cam follower 126 which is pivoted to the frame of the machine at 128. Cam follower 126 is maintained in contact with its associated cam lobe 56 (FIGURE 3) by a spring 130. FIGURES 5 and 6 show that arm 122 is connected at its end remote from the follower 126 to a rack 132 which is slidably mounted in a sleeve 134. A pinion gear 136 is provided on the lower end of the post 102 and slidably mounted thereon. It will be appreciated that when the arm 104 is actuated to a raising position by the follower 110 and the cam groove 60, the yoke 106 and the adjacent pinion gear 136 will be raised upwardly till the pinion engages or is in a position to be engaged by the rack 132. Subsequently, the cam follower 126 is engaged by its associated lobe 56 to draw on the arm 122 and thereby rotate the pinion 136 by drawing outwardly on the rack resulting in turning of the post 102, 180. This is subsequent to the operation of the post 102, its cross head 106 and the gripper 116 being raised upwardly. As shown in FIGURE 3, arm 124 is connected to a pivoting arm 138 which is adapted to swing the pneumatic device 120 and its associated dies 118 to the inoperative position shown in FIGURE 2.

OPERATIONAL SEQUENCE In operation, actuation of the drive means 34, through the working of 11? hain 38 and sprocket 40, brings the dies 14 in engagement with one another and, if utilized, the cores 12. This is effected through the action of the rocker arms 18 and their associated roller type followers 22 acting on the cam lobes 52 and 54. At this position, the trimming device 6 is in the position shown in FIG- URE 2 with the gripper on one of the arms 112 in position over the dies and in communication with the cavity therein. Further rotation of the cam shaft brings the pot into operative position through the arrangement of the cam lobe 62, arm 34 and nozzle 78. An injection is then made by means of the pneumatic device 74 and piston 70 acting in the chamber 76. The arm 94 is then pivoted so that the nozzle 78 is drawn away from the dies, the dies 14 and cores 12 are pulled apart by spring means (not shown), cam groove 60 actuates arm 104 to raise the post 102 and the cross head thereby lifting the casting from the cavity of the dies and cam follower 126 actuates arms 122 and 124 to rotate the post 102 and the cross head arms 112 and 114, 180 with respect to one another. These arms are then dropped downwardly as the cam follower progresses along its groove 60 and the secondary dies 118 are then brought into operative position over the casting and actuated by the device 120.

It will be appreciated that the apparatus of the present machine provides an economical manner of trimming castings inasmuch as such trimming is accomplished during the production of the casting itself and does not constitute a separate operation.

I claim:

1. A die casting machine comprising a frame; at least a pair of dies and means for supporting and guiding them on said frame; a pot for retaining a molten casting metal pivotally secured to said frame; means for injecting a portion of said casting metal from said pot into said dies, said injecting means being integrally formed with said pot; trimming means for removing a casting from the cavity of said dies and for removing flashing and the like from said casting; and a drive mechanism with (a) means for actuating said dies to operative and inoperative positions,

(b) means for pivoting said pot and its associated injection means into operative and inoperative engagement with said dies, and

(0) means for operating said trimming means.

2. A die casting machine according to claim 1, wherein said drive means comprises a shaft having a plurality of lobes and cam grooves thereon, a first pair of lobes adapted to actuate cores, a second pair of lobes being adapted to actuate said dies; a further lobe for actuating said trimming means; a first groove for actuating a portion of said trimming means and a second groove for pivoting said pot.

3. A die casting machine according to claim 2, wherein the trimming device includes a post member mounted for vertical sliding movement in said frame, a cross head on the upper end of said post having a pair of arms with depending gripping members at each end of said arms; a yoke and actuating arm operating on the lower end of said post responsive to one of said cam grooves; and means for rotating said post in said frame whereby said gripping members are rotated with respect to said post; and a pair of secondary dies mounted on said frame for removing flashing and the like from said castings.

References Cited UNITED STATES PATENTS 3,328,853 7/l967 Pekrol l64262 3,452,805 7/1969 Morin 164l54 J. SPENCER OVERHOLSER, Primary Examiner ROBERT D. BALDWIN, Assistant Examiner US. Cl. X.R. 1643l8, 340 

